Gut Microbiota-Derived Short-Chain Fatty Acids in Inflammatory Bowel Disease: Mechanistic Insights into Gut Inflammation, Barrier Function, and Therapeutic Potential

This review delves into the complex relationship between short-chain fatty acids (SCFAs) produced by the gut microbiota and inflammatory bowel disease (IBD). IBD, which includes Crohn's disease and ulcerative colitis, is a group of chronic gastrointestinal disorders with an increasing global incidence. Despite extensive research, the exact etiopathogenesis remains elusive, although a complex interplay involving genetic predisposition, environmental influences, and abnormal immune responses against commensal gut microbes is widely recognized. SCFAs, primarily acetate and butyrate, emerge as key microbial metabolites derived from the fermentation of dietary fiber. They exert profound effects on gut homeostasis, notably with butyrate serving as an essential energy source for colonocytes, strengthening epithelial integrity, actively modulating local and systemic immune functions, suppressing the expression of pro-inflammatory cytokines, and enhancing mucosal defense mechanisms. However, clinical trials exploring SCFA administration have frequently yielded variable and inconsistent results due to differences in study design and patient characteristics. This review thoroughly analyzes the diverse roles of SCFAs in the large intestine, focusing on the intestinal barrier, immune modulation, and microbiota. It critically examines the therapeutic potential of SCFAs, including acetate and propionate, in addition to the well-known butyrate, in IBD management.